【作者】 孔丽丽；

【导师】 刘山洪；

【作者基本信息】 重庆交通大学 ， 结构工程， 2011， 硕士

【摘要】 混凝土的裂缝修复问题,长期以来一直是学术界和工程界所研究的一个重要课题。通常认为,混凝土结构中存在着两种裂缝：肉眼看不见的微观裂缝和肉眼看得见的宏观裂缝。宏观裂缝都是由微裂缝发展而来的。本文主要研究对微裂缝的自修复。本文根据现有混凝土裂缝胶黏剂的性质、特点及用途,以尿素、甲醛(或添加三聚氰胺的改性脲醛树脂)为壁材原料,以双酚A型环氧树脂为芯材原料,采用原位聚合法合成以聚脲甲醛包覆的环氧树脂的微胶囊。通过普通混凝土试件与内置微胶囊的混凝土试件以及内置微胶囊的纤维混凝土试件的试验,得出了微胶囊对混凝土试件自身强度的影响及其修复效果。主要研究结论如下：①在查阅与分析了大量国内外文献资料的基础上,提出了微胶囊对混凝土裂缝的自修复机理,并且通过实验室合成了微胶囊；②内置7%-10%微胶囊对纤维混凝自身强度有增强的效果,而对于普通混凝土不能确定微胶囊对其自身强度的影响；③测定试件的抗折比以及压折比。内置7%-10%微胶囊的纤维混凝土抗折比提高,压折比将低,说明提高了纤维混凝土的柔韧性。因此,微胶囊为纤维混凝土起到了修复的作用。④测定试件的抗渗性。普通混凝土中添加纤维可使水的渗透高度减少24.4%；在纤维混凝土中添加7%的微胶囊可使渗水高度减少11.8%；添加10%的微胶囊可使渗水高度减少26.5%。因此,微胶囊为纤维混凝土起到了修复的效果。更多还原

【Abstract】 For a long time,the problem of repairing the concrete cracks is seen as an important topic in research in the academic field and engineering field. It is often believed that, there are two kinds of cracks in concrete structures:Microscopic cracks that cannot be seen by eyes and macroscopic cracks that can be seen by eyes. All the macroscopic cracks developed from microscopic cracks. This paper mainly studies the self-repairing of the microscopic crack.According to the properties,characteristics and usages of concrete crack adhesive,by using the urea and the formaldehyde (or the urea resin added with melamine) as wall materials and the epoxy resin of bisphenol type A as core material, through the method of in situ polymerization, the microcapsule of epoxy resin can be produced,which is wrapped by the uranium. Through the tests of the test pieces of common concrete, concrete with microcapsule inside, fiber concrete with microcapsule inside, we can find out the effluence of microcapsule towards the strength of the test piece of concrete and the result of self-repairing of the microcapsule. The main researching conclusions are as follows:①On the basis of consulting and analyzing enormous overseas and domestic documents, we came up with the self-repairing mechanism of microcapsules on concrete cracks,and synthesized microcapsule in the laboratory;②The built-in microcapsule of 7%～10% could enhance the strength of the fiber concrete,but could not be clear of the microcapsule effect on the strength of ordinary concrete;③Testing the flexural ratio and crushing ratio of the test piece. The fiber concrete with microcapsule of 7%～10% had the flexural ratio improved and the crushing ratio reduced. It was evident that the microcapsule has improved the flexibility of fiber concrete. Therefore,microcapsule exerted repairing effluence on the fiber concrete.④Testing the permeability of the test piece. By adding fiber in ordinary concrete, we could reduce the height of water penetration by 24.4 percent; by adding 7% microcapsules in fiber concrete could reduce the height of water penetration by 11.8 percent; by adding 10% microcapsules in fiber concrete can reduce the height of water penetration by 26.5 percent. Therefore,the microcapsule could help to repair the fiber concrete.更多还原